It was the August bank holiday three years ago and I was showing my Polish girlfriend one of the jewels of Britain's heritage. She was, undeniably, right.

Because Stonehenge, so far as you can tell from the distant perimeter rope where the public are kept back like undesirables outside a feast, sums up quite a lot about British tourist attractions: they are always smaller than you expect and usually a bit rubbish.

Where America has Disneyland, Mount Rushmore and the Statue of Liberty, we have nudist beaches in Scotland, the William and Kate walking tour and the Premier Inn honeymoon package. Yet, for some reason, it is their lack of ambition that makes us rather proud of them. Standing with Maria, who was looking somewhere between disappointed and contemptuous, I realised that what was needed was a guide to Britain's worst tourist attractions. On the sullen, silent train journey home I came up with Crap Days Out.

After months of subjecting myself to waxworks exhibitions, "destination" shopping malls and Britain's only museum of creationism, however, I realised that documenting the very worst that Britain has to offer was a job too big for one man. So I roped in my ex-flatmate, Jon Parker. We bought more than 30 guide books to Britain, joined internet forums and scoured the websites of town councils, sporting bodies and local historical associations to track down the obscure one-room museum as well as the big-name theme park. Over the course of a year we visited too many to remember – there are more than 200 days out in the book, ranging from "ludicrous" to "how can they sleep at night?" – and had a generally miserable time.

Mostly when I explained the project to people they would become very excited and ask if we were including the horrific local attraction that had blighted their childhood. Had it not been for tip-offs I would never have heard of the Isle of Wight garlic festival or the Isle of Man's Old House of Keys. Indeed, it became clear that the very words "Isle of" had a certain portent about them. They came to suggest a sense of proud localism that dried up on the mainland 100 years ago when people started moving to other counties for work, rather than other villages. That Wight is so proud of its output of Allium sativum makes you wonder why the maids of Kent no longer exult in hop harvests, or the men of Harlech sing no more of defending Wales against Norman invaders.

The attractions generally fell into two camps: awful by accident or awful by design. It is not Edinburgh's fault that Hogmanay rolls around at the coldest part of the year in one of the chilliest parts of Britain; it certainly is Madame Tussauds' fault that it charges nearly £30 for an adult ticket to view what amount to novelty candles, making the attraction one of the few places where a slow-burning fire would be welcome.

Statistical analysis proves that London, unsurprisingly, is the epicentre of the deliberately evil camp. It is the capital's stranglehold on tourism that enables Buckingham Palace to charge taxpayers, who are already paying for the upkeep of the state rooms, up to £65 to see their money being spent on corgis. The most accidentally disappointing region turned out to be the south-west, with the Somme-like conditions of the Glastonbury festival competing avidly with the Cerne Abbas Giant hill carving – which is invisible unless you are 130ft tall – and the curious optimism of the Bournemouth sewage works tour.

Scotland, however, is the surprise success story of the book, punching above its weight with around 20 entries. It even crosses into the territory of imaginary attractions, enticing thousands of people each year to spend days sitting beside Loch Ness trying to spot something that they know doesn't exist.

Among the dross we also found a few gems. The museum of creationism was the Genesis Expo in Portsmouth. It provided a fascinating insight into a system of belief that gets short shrift in the mainstream press. It is wrong to base opinions purely on prejudice, so it was pleasing to visit and have all my prejudices confirmed by evidence.

I also became strangely fond of Birmingham's Wattelisk. Surely one of the oddest ways imaginable to commemorate a 19th-century engineer who helped drive the industrial revolution is to produce a statue of him in the form of a large stone totem pole. But that didn't stop the visionary sculptor behind this piece of extraordinary silliness dedicated to James Watt. It might be just what Watt would have wanted – but then again it might not.

There were also some places we were unable to visit. We wanted to go to the Lapland New Forest theme park. It had, however, shut down six days after opening and by the time we were writing the book its owners were being successfully prosecuted for misleading the public and making hundreds of children cry. Instead we had to rely on eyewitness accounts, such as that from one woman who told the press: "Two fake large plastic polar bears were hidden behind a chain link fence, the nativity scene was a large picture far across an inaccessible muddy field and the majority of the food was out of fairground vans selling frozen burgers. I thought this was the introduction, I didn't realise I was inside."

The raw experiences of our visits were supplemented with painful, until-then-suppressed memories from childhood of being stuck in bank holiday traffic for hours with the distant promise of seeing half-cut morris men stagger about a village fete. Again, talking to people over the year, it became apparent that these were shared experiences that cut across geography, social class and age, proving an underlying national unity far stronger than that seen at all the royal weddings of the past 100 years put together.

Overall, though, we tried not to make the book too nasty – it gets nasty at times, but mostly when the attraction itself is a bit nasty. Really we were documenting something about Britain: the fact that it's smaller than you think and often a bit rubbish. But it keeps smiling while it's bumbling along without a great deal of ambition.

FATAL ATTRACTIONS

1 MADAME TUSSAUDS, LONDON

By rights, spending £28 for an hour of looking at shop dummies dressed as quite famous people should be the sort of thing you do when you have exhausted every other activity on the planet. Yet the queues outside Madame Tussauds are longer than those turning out to praise Chairman Mao on his birthday. Madame T began her trade during the French Revolution, making death masks of those guillotined. The families of the departed wanted something to remember their loved ones by and apparently nothing said "happy memories" like a wax impression of dad screaming in terror as a massive steel blade severed his neck.

2 STONEHENGE, WILTSHIRE

A very disappointing bit of henge-work. You get all keyed up for a gem of Neolithic history and when you finally arrive you realise that it's just a bunch of rocks standing up in a field. No one really knows what the stone circle was for, although one thing is certain: whoever built it was very keen on ditches. Still, you can experience it all from the comfort of your car because the busy A303 and the furiously busy A344 intersect within spitting distance of the stones, providing a lively sonic backdrop to the scene.

3NUDIST BEACH, BRIGHTON

Swimming starkers is the right of every Briton due to the campaigning of Brighton Conservative councillor Eileen Jakes, who in 1979 followed where the barons of the Magna Carta had led by starting a campaign to allow the people of Brighton to get wet and salty in the buff. But it was not without controversy. As one opposing council member put it: "I personally have no objection to people showing their breasts and bosoms and general genitalia to one another. But for heaven's sake, they should go somewhere more private."

Jon Parker

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